Field of the Invention
The present invention relates to a printing system, a control method thereof, a control apparatus, and a non-transitory computer-readable storage medium and, more particularly, to a method of making a crease at a pressure corresponding to the creasing purpose when performing creasing.
Description of the Related Art
Recently, it is becoming popular to perform crease processing on a printed material bound by case binding or the like, or a printing sheet to undergo fold processing (to be referred to as a “medium” hereinafter) by using an image forming apparatus such as a digital multi-function peripheral. Creasing is processing of making a crease on a medium before performing fold processing. For example, in case binding, creases are made at the edges of a case binding spine so that the folds at the edges of the spine can look fine, improving the quality of the bound printed material. A crease made at a fold position will be called a “crease for a spine edge (crease for a fold)”.
Creasing is also used to prompt the user to make a crease in advance at a position where a fold is to be made. For example, case binding often uses a thick medium as a cover. By making a crease on a cover in advance, the user can easily open the cover. When a cover and inner sheets are glued in case binding, a force is applied to the gluing position at the time of opening the cover, and the cover may readily come unstuck. To prevent this, a crease is made at a location spaced apart from the gluing position so that no force is applied to the gluing position even when the user opens the cover. A crease made at a position where the user is requested to make a fold will be called a “crease for a hinge”.
Although the “crease for a spine edge (crease for a fold)” and the “crease for a hinge” are made by crease processing that is performed on one medium, an appropriate pressure at which a creasing blade is pressed when forming each crease is different. For example, when a sheet having a grammage of 250 gsm to 300 gsm is used as a case binding cover, it is desirable to make a fold at a high pressure so that the user can easily fold back the cover. In this case, the pressure for the “crease for a hinge” is preferably about 140 Kgf. To the contrary, for the “crease for a spine edge (crease for a fold)”, a crease is made at a fold position in advance before fold processing, improving the fold quality. At this time, if a fold for the “crease for a spine edge (crease for a fold)” is made at the same pressure as that for the “crease for a hinge”, a creasing trace remains remarkable, degrading the fold quality. To prevent this, the pressure for the “crease for a spine edge (crease for a fold)” is preferably about 70 to 120 Kgf, which is lower than the pressure for the “crease for a hinge”.
In a method disclosed in Japanese Patent Laid-Open No. 2012-126472, a crease target medium is creased at a pressure force corresponding to the medium by adjusting, based on sheet information of the target medium, the pressure force of a driving unit that performs crease processing. The method disclosed in Japanese Patent Laid-Open No. 2012-126472 makes a crease based on sheet information of a medium and can perform crease processing at a pressure corresponding to the medium.
In Japanese Patent Laid-Open No. 2012-126472, crease processing is performed at the same pressure for the same medium. Hence, when a single medium is creased a plurality of times, the pressure cannot be controlled in accordance with creasing purposes such as the “crease for a spine edge (crease for a fold)” and the “crease for a hinge”.
The present invention has been made to solve the above-described problems, and provides a method capable of changing the creasing pressure even for a single medium in accordance with each creasing purpose by executing creasing at a pressure corresponding to the creasing purpose.